Antiknock fluids



tedf tates The instant invention relates to "improved antiknock fluidswhich, when blended in fuels for internal combustion engines, provideproducts of superior performance qualities. This application is acontinuation-in-part of my co-pending application, Serial No. 313,615,filed October 7, 1952, and now abandoned.

Shortly after the pioneering discovery of the antiknock efiectiveness oforganolead compounds, particularly tetraethyllead, it became apparentthat commercial utilization of such antiknock agents depended uponproviding a method for reducing the amount of lead salts whichaccumulated on engine parts. Accordingly, this reduction in thedeposition of lead saltshas been accomplished by providing correctiveagents or scavengers for use with organolead antiknock agents. Suchmixtures of organolead antiknock agents and scavengers are known in theart as antiknock fluids. The use of fuels containing these antiknockfluids causes the lead to be converted to fairly volatile lead saltswhich are discharged from the engine in the exhaust gas stream. Manycorrective agents or scavengers have been proposed of which the mostsuccessful have been organic bromine and chlorine compounds, notablyethylene dibromide and ethylene dichloride. Thus, for commercialpurposes, the most suc cessful antiknock composition for use in aviationfuels has been a mixture of tetraethyllead and ethylene dibromide, thedibromide being present in an amount of one theory, which is thequantity theoretically required to stoichiometrically react with all thetetraethyllead to form lead dibromide. Such a composition has twobromine atoms for each atom of lead. In the case of automotive fluids,the most efficacious composition comprises tetraethyllead in admixtureswith one-half theory of bromine as ethylene dibromide and one theory ofchlorine as ethylene dichloride. However, in spite of the highefiiciency of scavenging produced by such compositions,

the deposition of a certain amount of lead salts on engine parts is notentirely prevented.

One of the more serious problems directly attributed to such deposits isspark plug failure, commonly termed spark plug fouling. This resultsfrom the formation on the spark plug insulators of deposits that aresomewhat electrically conductive, thereby unduly lowering the electricalresistance between the spark plug electrodes. When this resistancebecomes too low, the production of a spark at the spark gap isprevented. To inhibit such spark plug failures, it has been proposed inthe prior art to utilize phosphorous-containing materials as additivesto leaded fuels. In this manner the lead deposits become converted tolead phosphates, which have higher electrical resistivities and are lessprone to cause spark plug fouling.

The phosphorus-containing materials have been proposed as additives tosupplement or to partially or totally replace halide scavengers.Although satisfactory engine operation can be obtained with suchcompositions, it has been found that the alleviation of spark plugfouling is attained at the expense of exhaust valve life. As will bemore apparent from the discussion hereinafter, this serious reduction inexhaust valve life is ultimately the result of exhaust valve burning andcorrosion which are promoted by such phosphorus-containing materialswhen Patented Sept. 12, 11961 employed in accordance with the teachingsof the prior art. More particularly this reduction in exhaust valve lifeis a reduction in the length of time during which the valve operateswithouteither excessive leakage or in extreme cases by mechanicalfailure because of the separation of the valve head from its stem. Sucheflects in turn result from corrosion and/or burning away of the valve,particularly at its head and throat area. The local removal of metalfrom the valve face causes valve leakage, and the removalof metal fromthe throat area can so Weaken the resistance of the valve to tensilestresses that the valve stretches in length and may even break apart.Corrosion and burning is most readily measured by the weight loss of thevalve.

Among the objects of the present invention is the provision of improvedantiknock fluids and fuels which obviate spark plug fouling and alsoimprove exhaust valve life. Other important objects of the presentinvention will become apparent from the following description of some ofits exemplifications.

It has-been discoveredthat excessive corrosion and burning of exhaustvalves caused by the addition of the phosphorous-containing spark pluganti-fouling compound to the above composition is strikingly decreasedby a critical increase in the organic bromine content of the scavenger.At the same time, this increase does not significantly impair any of theother operating or storage characteristics of the fuels or fluids.

This eflect is quite unexpected since in the absence of thephosphorus-containing material, an increase in halogen content, andparticularly bromine, was known to cause excessive exhaust valvecorrosion and burning. For some unexplained reason, however, when theadded bromine content is-present along with the phosphorus compounds,neither is eifective to produce the expected corrosion and burning. Onthe other hand, the phosphorus compounds in such a composition stillproduce their antifouling results.

The critical increase in the organic bromine content of the scavengerused in combination with the phosphorus-containing, organoleadcompositions according to this invention is a 15 to 20 percent increaseabove the bromine scavenger content used in standard commercialpractice. in aviation applications, this practice has been the provisionof one theory of bromine as a bromine scavenger, the brominezlead atomratio therefore being 2:1. In automotive applications, this practice hasbeen the provision of 0.5 theory of bromine as a bromine scavenger and1.0 theory of chlorine as a chlorine scavenger, in which case thebromineglead atom ratio was 1:1.

According to this invention greatly enhanced engine performance isachieved by improving an antiknock composition consisting essentially oforganolead material as the principal antiknock ingredient, organichalogen scavenger material of the class of that providing two atoms ofchlorine plus one atom of bromine per atom of lead, and that providingtwo atoms of bromine per atom of lead, and a phosphorus-containing sparkplug antifouling compound, the phosphorus-to-lead atom ratio of saidcomposition being from about 0.02:3 to about 0.7 :3 by increasing thebromine content of the organic halogen scavenger material by about '15to 20 percent.

One embodiment of this invention is an antiknock composition consistingessentially of an organolead antiknock compound-preferably a lead alkylantiknock compounda phosphorus-containing spark plug anti-fouling a)compound present in amount such that the phosphorusto-lead atom ratio ofsaid composition is from about 0.02:3 to about 0.7:3, andan organichalogen scavenger complement selected from the group consisting of (1)an organic bromine scavenger capable of reacting with the lead duringengine combustion to form volatile lead salts containing bromine andpresent in amount such that the bromine-to-lead atom ratio is from about2.3:1 to about 2.4:1; and (2-) a mixture of an organicchlorine'scavenger and an organic bromine scavenger. capable of reactingwith the lead during engine combustion to form volatile lead saltscontaining chlorine and bromine, .said organic chlorine scavenger beingpresent inamount'such that the chlorine-to-lead atom ratio is about-2:1andasaid organic bromine scavenger being present in amount such that thebrornine-to-lead atom ratio is from about 1.15:1 to about 1.2:1. Anotherembodiment of this invention is hydrocarbons of the gasoline boilingrange containing an antiknock quantity of the above antiknockcompositions. Such antiknock quantity ranges from about 0.5 to about 6.3grams of lead per gallon of gasoline.

The amount of'phosphorus-containing. material used is generally betweenthe limits of 0.01 to 0.35 theory of phosphorus, one theory ofphosphorusbeing defined in the amount of phosphorus theoretically required toreact with the lead to form lead orthophosphate, which quantity is twoatoms of phosphorus per three atoms of lead. On a pho'sphorus-to-leadatom ratio basis, the above amounts to from 0.02:3 to 07:3. Particularlyfavorable results can be obtained with amounts of phosphoruscontainingmaterials contributing at'least 0.05 theory of phosphorus. More than 0.2theory of phosphorus is not as desirable as the lower concentration. Ona phosphorusto-lead atom ratio basis, this particularly favorable rangeis from 0.1:3 to 0.4:3.

The above improvements are obtained without exception from all types ofphosphorus compounds that are soluble in the fuel in the aboveproportions. It is preferable to use organo-phosphorus materials, thatis, materials in which phosphorus is linked either directly to a carbonatom in an organic radical, or is linked to an organic radical throughoxygen, nitrogen or sulfur. However, inorganic compounds, such astriphosphonitrilic chloride ({PNCl l and tetraphosphorus trisulfide (1,8 are also eiiective. The organic phosphorus-containing materialsinclude phosphines and related compounds; halophosphines; halophosphinehalides and phosphonyl halides; quaternary phosphonium compounds;tertiary phosphine oxides and sulfides; phosphinou-s, phosphonous andphosphonic acids, the sulfur analogs and esters of the aforesaid acids,phosphites and thiophosphites; phosphates; halophosphates and thioanalogs; compounds with phosphorus-to-nitrogen bonds; and derivatives ofanhydro phosphorus acids.

As used in the discussion hereinafter, the term organic radicals denotesa univalent aliphatic, alicyclic or aromatic radical which can befurther substituted with negative radicals, such as hydroxy, halide andthe like. By the term univalent aliphatic radical is intended aunivalent radical derived from an open chain saturated or unsaturatedcarbon compound, that is, an acyclic radical. The term univalentalicyclic radical denotes a monovalent radical derived from thecorresponding aliphatic compounds by ring formation. The term univalentaromatic radical denotes a monovalent radical derived from a compound ofthe benzene series containing a ring with the peculiar type ofunsaturation inherent in such aromatic compounds.

Thus, when the organic radical or radicals of the organo-phosphorusmaterials of the improved antiknock fluids of the present invention is aunivalent aliphatic radical or radicals, such can be a radical orradicals selected from the group consisting of alkyl, alkenyl, aralkyl,and aralkenyl. Consequently, when the organic radical or radicals of theorganophosphorus materials described hereinafter is a univalentaliphatic radical, it can be an alkyl radical, such as for example,methyl, ethyl n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl,t-butyl, n-amyl, and the various positional isomers thereof as, forexample, l-methylbutyl; 2-methylbutyl; 3-methylbuty1; 1,l-dimethylpropyl; 1,2-dimethylpropyl; 2,2-dimethylpropyl andl-ethylpropyl, and likewise the corresponding straight and branchedchain isomers of hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl,tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octodecyl,nondecyl, eicosyl and thc'like. In addition, the univalent aliphaticradical or radicals of the organophosphorus materials of the improvedantiknock fluids of this invention can be an alkenyl radical, such asfor example, ethenyl; n -propenyl; A prop'enyl; isopropenyl; A -buteny1;LW-butenyl; A -butenyl, and the corresponding branched chainv isomersthereof as, for example, A -isobutenyl; M-isobutenyl; A -secbutenyl; o-sec-butenyl; Al-pentenyl; A -pentenyl; A pentenyl; M-pentenyl, and thecorresponding branched chain isomers thereof; Abhexenyl; A -hexenyl; A-hexenyl; n -hexenyl; A -hexenyl; and the corresponding branched chainisomers thereof, including 3,3-dimethyl-A -butenyl; 2.,3-dimethylA-butenyl; 2,3-dimethyl-.A -butenyl; 2,3-dimCithYlPA -bUtEHYI; and1-methyl-l-ethyl-A -propenyl; and similarly, the various isomers ofheptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl,tetradecenyl, pentadecenyl, hexadecenyl, heptadeoenyl,octodecenyhnondecenyl, eicosenyl, andv the like. Moreover, when theorganic radical or radicals of the organophosphorus materials describedhereinafter is a univalent aliphatic radical, it canbe an :aralkylradical, such as for example, benzyl; u-phenyl-ethyl', B-phenyl-ethyl;a-phenylpropyl; B-phenyl-propyl; 'y-phenyl-propyl; a-pheny-l-isopropyl;fi-phenyl-isopropyl; a-phenyl-butyl; fi-phenyh butyl; -phenyl-butyl;6-phenyl-butyl; u-phenyldsobutyl; fl-phenyl-isobutyl; -phenylsisobutyl;a-phenyl-sec-butyl; B-phenyl-sec-butyl; 'y-phenyl-sec-butyl;fl-phenyl-t-butyl; a-naphthyl-methyl', 5'-naphthyl-methyl;u-(a'-naphthyl)- ethyl; a-(5-naphthyl)-ethyl; fi-(d-naphthyD-ethyl;fi-(finaphthyl) -ethyl; ozoU-naphthyl -propyl; a-( fl-naphthyl) p p B-(P y )-p py fi-(fi'-n p y )p py 'v- (a'-naphthyl)-propyl; 7(fi-naphthyl)-propyl; a (en'- naphtl1yl)-isopropyl;'rx-(ff-naphthyl)-isopropyl; a-(cdnaphthyl)-butyl;a-(fi'-naphthyl)-butyl; B-(M-naphthyD- butyl; B-(d-naphthybbutyl;'y-(a'-naphthyl)-butyl; 'y-(B' naphthyl)-butyl; 6-(ix-naphthyl)-butyl;6-(B'-naphthyl)- butyl; oc-( a'-naphthy1)-isobutyl;a-(fl'-naphthyl)-isobutyl; fi-(oU-naphthyl)-isobutyl;fl-(H-naphthyl)-isobutyl; 'y-(oc'- naphthyl)-isobutyl;'y-(H-naphthyD-isobutyl; m-(d-naphthyl)-sec-butyl; a (,8-naphthyl)-sec-butyl; B (a'-naphthyl)-sec-butyl; 5-(B'-naphthyl)-sec-butyl; 'y-(of-naphthyl)-sec-butyl; '7-(B'd'laPhlZhYD-SGC-blllYl; ,8-(ad-naphthyl)-t-butyl; B-(,8'-naphthyl)-t-butyl; the corresponding a'and ,8'-naphthyl derivatives of n-amyland the various positional isomersthereof such as, for example, said derivatives of l-rnethyl-butyl;2-methyl-butyl; 3-methylbutyl; 1,1-dimethyl-propyl; 1,2-dimethyl-propyl;2,2-dimethyl-propyl; l-ethyl-propyl, and likewise said derivatives ofthe corresponding isomers of hexyl, heptyl, octyl, and the likeincluding eicosyl Other such aralkyl radicals of the organophosphoruscompounds of the improved antiknock fluids of this invention include thea-, fi-, and 'y-anthryl derivatives of alkyl radicals, such as forexample, u'-anthryl-methyl; a-(;8'-anthryl)-ethyl; B-(vanthryl)-ethyl; a(a-anthryl)-butyl; B (B-anthryl)-2- methyl-amyl, and the like, and thecorresponding alkyl derivatives of phenanthrene, fluorene, acenaphthene,chrysene, pyrene, triphenylene, naphthacene, and the like. Moreover, theunivalent aliphatic radical or radicals of the organophosphorusmaterials of the improved antiknock fluids of the instant invention canbe an aralkenyl radical such as for example a-phenyl-ethenyl;fl-phenylethenyl; a-phenyl-n -propenyl; ,3-phenyl-A -propenyl;'yphenyl-N-propenyl; a-phenyl-A propenyh fi-phenyl-d aeeavse propenyl;'y-phenyl-A -propenyl; a-phenyl-isopropenyl; 8- phenyl-isopropenyl;-y-phenyl-isopropenyl; and similarly the phenyl derivatives of theisomers of butenyl, pentenyl, hexenyl, heptenyl, and the like, up to andincluding about eicosenyl. Other such arylalkenyls includea-(oU-naphthyl) -ethenyl; a-(B-naphthyl)-ethenyl; fi-(oJ-naphthyD-ethenyl; ,8 (B'-naphthyl)-ethenyl; a (a'-naphthy1) -A propenyl; a-(3'-naphthyl) -A -propenyl; B-(oU-naphthyD- a -propenyl;fi-(fi'-naphthyl)-A -propenyl; -a- (a'-naphthyl)-A -propenyl;a-(fl'-naphthyl)-A -propenyl; (a'- naphthyD-M-propenyl;;8-(fi-naphthyl)-A -propenyl; a- (a'-naphthyl)-isopropenyl; u(,B'-naphthyl) -isopropenyl; fi-(cU-naphthyl)-isopropenyl;B-(fl'-naphthyl)-isopropenyl, and the like. In addition, such aromaticderivatives of alkenyls, that is, aralkenyl radicals include derivativesof phenanthrene, fluorene, acenaphthene, chrysene, pyrene, triphenylene,naphthacene, and the like.

When the organic radical or radicals of the organophosphorus materialsutilized in the improved antiknock compositions of the present inventionis a univalent alicyclic radical or radicals, these can be selected fromthe group consisting of cycloalkyl and cycloalkenyl radicals. Thus, theunivalent alicyclic radicals can be cycloalkyl radicals, such as rforexample, cyclopropyl, cyclobutyl, cycloamyl, cyclohexyl, cycloheptyl,cyclooctyl, cyclononyl, cyclodecyl, cycloundecyl, cyclododecyl,cyclotridecyl, cyclotetradecyl, cyclopentadecyl, cyclohexadecyl,cycloheptadecyl, cyclooctadecyl, cyclononadecyl, cycloeicosyl, and suchcycloaliphatic radicals as a-cyclopropylethyl, B-cyclopropylethyl,a-cyclobutylpropyl, fi-cyclobutylpropyl, 'y-cyclobutylpropyl,a-cycloamylisopropyl, flcycloamylisopropyl, and the like. Similarly, thealicyclic radicals of the organophosphorus materials of the im-.

proved antiknock fluids of the present invention can be cycloalkenylradicals, such as for example, m-cyclohexylethenyl; B-cyclohexylethenyl;a-cycloheptyl-A propenyl; 'y cycloheptyl-N-propenyl; oz cyclooetyl-a-propenyl; ficyclooctyl-A -propenyl; 'y-cyclooctyl-A -propenyl;B-cyclononylisopropyl; a-methylene-fl-cyclododecylethyl, and the like.

When the organic radical or radicals of the organophosphorus materialsof the improved antiknock fluids of the present invention is a univalentaromatic radical or radicals, these can be selected from the groupconsisting of aryl and alkaryl radicals. Thus, the univalent aromaticradical or radicals can be aryl radicals, such as for example,ocnaphthyl, fl-naphthyl, a-anthryl, B-anthryl, y-anthryl, and the like,including the various monovalent radicals of such aromatic as indene,isoindene, acenaphthene, fluorene, phenanthrene, naphthacene, chrysene,pyrene, triphenylene, and the like. Moreover, the univalent aromaticradical or radicals can be alkaryl radicals, such as for example,o-tolyl, m-tolyl, p-tolyl, 2,3- xylyl, 2,4-xylyl, 2,5-xylyl, 2,6-xylyl,3,4-xy1yl, 3,5-xylyl, o-cumenyl, m-cumenyl, p-cumenyl, mesityl,o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, 2-methyl-u-naphthyl, 3-methyl-u-naphthyl, 4-methyl-a-naphthyl, S-methyl-a-naphthyl,6-methyl-a-naphthyl, 7-methyl-u-naphthyl, 8-methy1- anaphthyl,l-ethyl-B-naphthyl, 3-ethyl-fi-naphthyl, 4- ethyl-fi-naphthyl,S-ethyl-fi-naphthyl, 6-ethyl-fi-naphthyl, 7-ethyl-fl-naphthyl,8-ethyl-fi-naphthyl, 2,3-dipr0pyl, otnaphthyl,5,S-diisopropyl-B-naphthyl, and the like.

The term phosphines and related compounds is considered herein as beinggeneric to such compounds as phosphines, biphosphines and phosphinemethylenes.

Phosphines are derivatives of trivalent phosphorus in which one or morephosphorus-to-carbon bond exists, with the remaining phosphorusvalences, if any, being bound by hydrogen. Therefore, phosphines can berepresented by the general formula can be the same or different and isselected from the group consisting DEE hydrogen and organic radicals.Illustrative examples of phosphine include ethylphosphine,

propylphosphine, isopropylphosphine, isobutylphosphine,isoamylphosphine, phenylphosphine, isopropenylphosphine, A-pentenylphosphine, a-phenylethylphosphine, 'y-phenylbutylphosphine,fi-phenylethenylphosphine, cyclohexylphosphine, o-tolylphosphine,3-methyl-a-naphthylphosphine, dimethylphosphine, methylethylphosphine,

diethylpho sphine, methylisopropylphosphine, ethylbutylphosphine,isopropylisobutylphosphine, diisoamylphosphine, methylphenylphosphine,diphenylphosphine, phenyl-m-tolylphosphine, sec-butylethenylphosphine,di-A -butenylphosphine,

dia-phenylpropyl) -phosphine, methyla-phenylethenyl) -phosphine,butylcycloamylphosphine, dicyclohexylphosphine, di-(2,3-xylyl)-phosphine, trimethylphosphine, tni-(chloromethyU-phosphine,triethylphosphine, triisopropylphosphine, tributylphosphine,triphenylphosphine,

tri( 2-chlorophenyl) -phosphine, tri- (Z-methylphenyl) -phosphine,dimethyl- (ethylphenyl) -phosphine, dimethylphenylphosphine,diethylpropylphosphine, diethylphenylphosphine, dipropylphenylphosphine,diallylphenylphosphine, diisobutylphenylphosphine,diphenylmethylphosphine, diphenyl-p-tolylphosphine,dicyclobutylphenylphosphine, ethylisopropylis obutylphosphine,

and the like.

Biphosphines are derivatives of phosphines containing aphosphorus-to-phosphorus bond which can be represented by the generalformulae wherein R is an organic radical and each of R R and R; can bethe same or difierent and is selected from the group consisting ofhydrogen and organic radicals. Illustrative examples of biphosphinesinclude tetraphenyl biphosphine, diphenyl biphosphine, tetramethylbiphosphine, and the like.

Phosphinemethylenes are derivatives of phosphines wherein the threeorganic radicals on the phosphorus atom are supplemented by a fourthgroup attached to the phosphorus by a semipolar bond. Illustrativeexamples of phosphinernethylenes include (C H P=C(C H (C H P=C(C H -o)and the like.

Halophosphines can be dihalophosphines or monohalophosphines representedby the general formulae wherein R is an organic radical and R ishydrogen: or

an organic radical; wherein each of X X and X can be the same ordifferent, and is selected from thegroup consisting of bromide,chloride, and iodide radicals. Thus, halophosphines include suchcompounds as, for example,

ethyldichlorophosphine, propyldichlorophosphine,isopropyldichlorophosphine, butyldichlorophosphjne,butyldibromophosphine, isobutyldichlorophosphine,isoamyldichlorophosphine, phenyldichlorophosphine,phenyldibromophosphine, phenyldiiodophosphine,4-chlorophenyldichlorophosphine, 4-brornophenyldichlorophosphine,4-methylphenyldichlorophosphine, 4-methylphenyldibromophosphine,4-111ethylphenyldiiodophosphine, 1 4-methylphenyldibromophosphine,2,4-dimethylphenyldichlorophosphine, a-naphthyldichlorophosphine,methylethylchlorophosphine, methylethylbromophosphine,methylethyliodophosphine, diethylchlorophosphine, diethylbromophosphine,diethyliodophosphine, dipropylchlorophosphine, dipropylbromophosphine,propyliodophosphine, methylphenylchlorophosphine,methylphenylbromophosphine, ethylphenylchlorophosphine,diphenylchlorophosphine, diphenylbromophosphine,

diphenyl -phosphine,

and the like.

Halophosphine halides and phosphenyl halides are halogen derivatives ofphosphorus in its higher oxidation wherein R is an organic radical andeach of R and R can be the same or different and is selected from thegroup consisting of hydrogen and organic radicals; each of X X and X canbe the sameior different: and is selected from the group consisting ofbromide, chloride and iodide radicals and Ch is a divalent radicalselected from the group consisting of oxygen, sulfur and selenium, thatis, a chalkogen. Illustrative examples of halophosphine halides includesuch compounds as ethyl phosphorus tetrachloride, propyl phosphorustetrachloride, isopropyl phosphorus tetrachloride, isobutyl phosphorustetrachloride, phenyl phosphorus tetrachloride, phenyl phosphorusdibrornidedichloride, 'phenyl phosphorus tetrabromide, 4- chlorophenylphosphorus tetrachloride, 4-chlorophenyl phosphorus dichloiidedibromide,4-bromophenyl phosphorus tetrachloride, 4-methylphenyl'phosphorustetrabrornide, Z-indenyl phosphorus tetrachloride, a-naphthyl phosphorustetrachloride, diphenyl phosphorus trichloride, (4-=bromophenyl)-phenylphosphorus trichloride, m-

tolyl phenyl phosphorus trichloride, {2,4,5-trimethylphenyl)-pheny1phosphorus trichloride, triethyl phosphorus dichloride, diethyl phenylphosphorus. dichloride, triphenyl phosphorus dichloride, triphenylphosphorus dibromide, tri-,(2,4,5-trimethylphenyl)-phosphorusdichloride, and the like. 1

Illustrative examples of phosphenyl halides include such compoundsasamethanmphosphonyl dichloride, ,8-

chloroethane phosphonyl dichloride, 3-hromoethane phosphonyl dichloride,propane phosphonyl dichloride, isobutane phosphonyl' dichloride,cyclohexane phosphonyl dichloride, dimethyl phosphonyl chloride,methylethyl phosphonyl chloride, diethyl phosphonyl chloride, benzenephosphonyl dichloride, 4-chhorobenzene phosphonyl dichloride,2-chloro-4-methylbenzene phosphonyl dichloride; 4-methylbenzenephosphonyl bromochloride, 2,4,5- trimethylbenzene phosphonyl dichloride,methylphenyl phosphonyl chloride, di-(phenyl)-phosphonyl chloride,hexanethiono phosphonyl dibromide, isobutane thiono phosphonyldichloride, methylcyclohexyl phosphonyl chloride, ethanethiono-phosphonyl dichloride, benzene phosphonyl dibromide, and the like.

Quaternary phosphonium compounds can he represented by the generalformula wherein R is an organic radical and each of R R and R., can bethe same or different and is selected from the group consisting ofhydrogen and organic radicals and X is selected from the groupconsisting of chloride, bromide, iodide and hydroxyl radicals.Illustrative examples of quaternary'phosphonium compounds includetetrarnethyl phosphoniumhydroxide, tetraethyl phosphonium chloride,tetrapropyl phosphonium iodide, tetraisopropyl phosphonium bromide,tetrabutyl phosphonium iodide tetraphenyl phosphoniurn iodide,tetraphenyl phosphonium bromide, tetraphenyl phosphonium hydroxide,tetra-ptolyl' phosphonium chloride, trimethylethyl phosphonium chloride,trimethyl-(B-bromoethyl)-phosphonium bromide,trirnethyl-(isoarnyl)-phosphoniurn iodide,trimethyl-(iodomethylene)-phosphonium chloride, triethylpropylphosphonium chloride, triethylphenyl phosphonium bromide, tripropylethylphosphonium, iodide, dimethylethylphenyl phosphonium. iodide,diethylmethylphenyl phosphonium iodide, diethylmethyl-rn-tolylphosphoniurn iodide, diisobutylethylphenyl phosphonium iodide,dimethyldiethyl phosphonium chloride, phenylethyltetramethylenephosphonium iodide, phenylethylpentamethylene phosphonium iodide, andthe like.

Tertiary phosphine oxides and sulfides are compounds consisting of threeradicals bound by phosphorus-carbon bonds to the phosphoryl andthiophosphoryl groups respectively. Thus, the compounds can berepresented by the general formula wherein R is an organic radical andeach of R and R .can be the same'or dhferentand is selected from thegroup consisting of oxygen and sulfur, that is,- a chalkegen.Illustrative examples of tertiary phosphoneoxides include such compoundsas trimethyl phosphine oxide, trichloromethyl phosphine oxide, triethylphosphine oxide, tripropyl phosphine oxide, triphenylphosphine oxide,tri- 2,3,-xylyl phosphine oxide, tri-3-indelyl phosphine oxide,dimethylethyl phosphine oxide, dimethylphenyl phosphine voxide,diphenylmethyl phosphine oxide, diphenylethyl phosphine oxide,methylethylphenyl phosphine oxide, methylpropylphenyl phosphine oxide,and the like. Illustrative examples of tertiary phosphine sulfidesinclude such compounds as trimethyl phosphine sulfide, triethylphosphine sulfide, triisohutyl phosphine sulfide, triphenyl phosphinesulfied, -tri-(4-methylphenyl)-phosphine sulfide, tri-(8-naphthyl)-phosphine sulfide, diethyl phosphine sulfide, ,diphenylethylphosphine sulfide, diphenyl-(isoamyl)-phospl1ine sulfide, and the like.-

Cornpounds of the generic term phosphinous, phosphonous and phosphenicacids, their sulfur analogs and esters of the aforesaid acids arecompounds possessing one or two organic radicals bound directly to thecentral phosphorus atom, the residual valences of which constitute anacid function or ester based on such acid function. Thus, in|general,--such substances can be primary or .secondaryphosphonicacids,-phosphonous acids, phosphiuous acids, the thio analogs of theaforesaid substances in which one or more oxygen atoms are replaced withsulfur including primary and secondary thiophosphionous acids, and theesters of all of the aforesaid acids invwhich one or more acidichydrogen atoms are replaced by organic radicals.

Phosphinous and thiophosphionous acids and esters thereof can berepresented by the general formula wherein each of R R and R, can be thesame or dif ferent and is selected from the group consisting of hydrogenand organic radicals but wherein not all of R R and R are hydrogen, andCh is a divalent radical selected from the group consisting of oxygenand sulfur, that is, a chalkogen. Illustrative examples of suchcompounds in clude diethyl phosphinous acid, diphenylbutyl phosphinite,dipropyl thiophosphinous acid, phenylpropylmethyl thiophosphinite,dicresylphenyl phos'phiuite and the like. Phosphonous andthiophosphonous acids and esters thereof can be represented by thegeneral formula R P( 1 2) z s) wherein each of R R and R can be the sameor different and is selected fromthe group consisting of hydrogen andorganic radicals but are not all hydrogen,

and each of Ch and Ch can be the same or different, and is selected fromthe group consisting of divalent 1 1) 2 2) s s); 4 5 4) -M 6) wherein Ris hydrogen or an organic radical and each of R R R R and R can be thesame ortdiiferent and is selected from the group consisting of hydrogenand organic radicals and each of Ch Ch Chg, Ch and Ch can be the same ordifferent and is selected from the group consisting of divalent oxygenand sulfur radicals, that is, chalkogens. Illustrative examples ofphosphonic and thiophosphonic acids and esters thereof include suchcompounds as diethylmethane phosphonate, dibutylbenzene phosphonate,diisopropylbutane phosphonate, diethylbenzene phosphonate, di (2ethylhexyl) benzene phosphonate, diphenylpropane phosphonate,dicresylbenzene phosphonate, benzene phosphonic acid, ethylphenylphosphonic acid, dimethylbutane thiophosphonate, methylethylbenzenethiophosphonate, diamylbenzene thiophosphonate, diphenylbenzenethiophosphonate, dicresylbenzene thiophosphonate, benzene thiophosphonicacid, ethylphenyl thiophosphonic acid, and the like.

Phosphites and thiophosphites are the esters of phosphorus acid andthiophosphorus acid. Thus, phosphites and thiophosphites can berepresented by the general formulae 1 2) 2 2) s s);

wherein R R and R are organic radicals and each of R R R R R and R canbe the same or difierent and is selected from the group consisting ofhydrogen and organic radicals, and each of Ch Ch Ch Chi Ch Ch Chq, Chgand Chg can be the same or different and is selected from thegroupconsisting of divalent oxygen and sulfur radicals, that is,chal-kogens. 'Illustrative examples of phosphites and thiophosphites ireelude such substances as monomethyl phosphite, monoethyl phosphite,monoisopropyl phosphite, dimethyl phosphite, diethyl phosphite, dipropylphosphite, diisopropyl phosphite, diisobutyl phosphite, trimethylphosphite, triethyl phosphite, tripropyl phosphite, triisopropyl phosphite, tributyl phosphite, tri-o-cresyl phosphite, triisoamyl phosphite,tri-o-cyclohexyl phosphite, triethyl thiophosphite, tripropylthiophosphite, tributyl thiophosphite, triphenyl thiophosphite,monoethoxydiethyl thiophosphite, diethoxymono thiophosphite, and thelike.

Phosphates, halophosphates and thio analogs are the esters of phosphoricacid and the esters of halides of phosphoric acid, including analogs ofsuch substances wherein either part or all of the oxygen atoms arereplaced by sulfur. =Thus, phosphates can be represented by the generalformulae wherein R R and R are organic radicals and each of R R R R Rand R can be the same or different and is selected from the groupconsisting of hydrogen and organic radicals and each of Ch Ch Chg, andCh; can be the same or different and is selected from the groupconsisting of oxygen and sulfur, that is, chalkogens. Illustrativeexamples of phosphates and thiophosphates include such compounds asdimethyl phosphate, tn'butyl phosphate, tri-o-cresyl phosphate,tri-m-cresyl phosphate,

tri-p-cresyl phosphate, phenyldicresyl phosphate, methyl- 1 1) X1 2; az) a a a wherein each of R and R are organic radicals and R hydrogen oran organic radical; each of Ch Ch and Ch can be the same or differentand is selected from the group consisting of divalent oxygen and sulfurradicals, that is, chalkogens, and each of X X2 and X can be the same ordifferent and is selected from the group consisting of fluoride,bromide, chloride and iodide radicals. Illustrative examples ofhalophosphates and halothiophosphates include such compounds asethyldifluorophosphate, methyldichlorophosphate, ethyldichlorophosphate,butyldichlorophosphate, isopropyldibromophos phate,ethyldifluorothionophosphate, ethylfluorochlorothionophosphate,methyldichlorothionophosphate, ethyldichlorothionophosphate,propyldichlorthionophosphate, butyldichlorothionophosphate,isobutyldichlorothionophosphate, ethyldibromothionophosphate,(S)-ethyldichlorothiothionophosphate, dimethylfluorothiophosphate,diethylfluorophosphate, dipropylfiuorophosphate,dimethylchlorothionophosphate, diethylchlorothionophosphate,dibutylchlorothionophosphate, di-(SS)-ethylfiuorodithiophosphate,di-(SS)-ethylchlorodithiophosphate, di-(SS)-ethylchlorodithiothionophosphate, phenyldichlorophosphate,2-1nethylphenyldichlorophosphate, Z-isopropyl-S-methylp-henyldichlorophosphate, 4-butyl-2-methylphenyldichlorophosphate,(4 tert-butylphenyl) dichlorophosphate, phenyldichlorothionophosphate,phenyldibromothionophosphate, (S)-phenyldichlorothiothionophosphate,diphenylfiuorophosphate, diphenylchlorophosphate,ethylphenylchlorophosphate, diphenylchlorothionophosphate,diphenylbromothionophosphate, diphenylchlorothiophosphate, and the like.

Compounds with phosphorus-to-nitrogen bonds are compounds containingsingle, double or semi-polar bonds, and are represented by amides ofphosphorus acid, phosphoric acid, the halides and esters thereof,phosphonic acids, and the thio analogs of each of the aforesaid classesof compounds. Furthermore, compounds with phosphorus-to-nitrogen bondsinclude a class of imido derivatives of the aforesaid classes ofcompounds as well as compounds known as phosphinimines which areessentially semi-polarly linked substances. Illustrative .eX- amples ofcompounds containing phosphorus-to-nitrogen bonds include suchsubstances as ethyl-N,N-dimethyldiamidophosphate;N,N'-diphenyldiamidophosphate; dichloro N,N di-ethylamidophosphate;N,N',N" triethylphosphoric triamide; N,N',N"-triethylphosphorus tri--examples of derivatives of anhydrophosphorus acids inelude suchsubstances as tetraethylpyrophosphite, tetrapropylpyrophosphite,tetrabutylpyrophosphite, tetrarnethylpyrophosphate,tetraethylpyrophosp'hate, tetraisopropylpyrophosphate,tetrabutylpyrophosphate, tetraethylpyrophosphonate, methyl-m-phosphate,ethyl-m-phosphate, phenyl-rn-phosp-honite and the like.

The general methods for the preparation of the organophosphoruscompounds fully enumerated hereinbefore, are known to those skilled inthe art. methods are fully described in kosolapoff, Organo PhosphorusCompounds." Although the preceding discussion with regard toorganophosphorus compounds has been concerned with pure phosphoruscompounds, there are available as articles of commerce, mixtures of thevarious positional isomers of given phosphorus compounds. Such mixturesare also within the spirit and scope of the present invention, for Ihave found that I can successfully employ in my improved antiknockfluids such mixtures as the various positional isomers of tributylphosphates, triamyl phosphates, tributyl thiophosphates, triamylthiophos phates, tricresyl phosphates, tritolyl phosphates, tripropylphosphites, tributyl phosphites, triamyl phosphites and the like.

The scavengers of the improved antiknock fluids of my invention can, inaddition to ethylene dibromide and ethylene dichloride, be thosedisclosed in. U.S. 1,592,954; 1,668,022; 2,364,921; 2,389,281;2,479,900; 2,479,901; 2,479,902; 2,479,903; 2,496,983. Illustrativeexamples of such additional scavengers include such substances as carbontetrachloride; hexylchloride; ethyl chloride; carbon tetraibromide;hexyl bromide; ethyl bromide; carbon tetraiodide; hexyl iodide; ethyliodide; propylene dibromide; butylene dichloride; trichloroanil ine;1,3,4-tribromopen tane; 4,5-dibromo-1,2-dirnethylbenzene;1,6-dibromohexane; 1,2,5 tribromopentene 1; 1,2,3-tribromopentane;1,2,3-tribromobutane; 3,4-dibron1omethylcyclohexane; 6- bromo-4-bromomethyl) heptenel; 1,2-dibromocyclohexane; 1,2,3-tribromo-2-methylpropane; (5-chloroamyl) benzene; 1,8-dichloroctane;1,2,4-triclllordbenzene; 2,4- dichloro-toluene; l-chlorooctane;4-bromo-i',2-dimethyl' benzene; 3-bromo-1,2-dimethylbenzene;l-bromo-4-ethyl benzene; 1,1-dichlorobutane; 1,4-dichlorobutane; 2,3-diohlorobutane; l,3-dichloropentane; 2,3-dichloropentane; 3,3dichloropentane; 1,3-dibromo-Z,Z-dimethylpropane;

Most of these general 12 3,4-dichloroc-umene; 2,4-clichlorotoluene;B,fl'-dibromodiethyl ether; a-bromobutyl-B-bromoethyl ether;B-chloroethyl-B-chloroisopropyl ether; and the like.

Any organic halides can the used as scavengers in accordance with thepresent invention so long as they do not resist decomposition by thecombustion in the cylinders. Some aryl chlorides, such asmonochlornaphthalene, are not good scavengers. 'For example, alkylhalides, aryl bromides and chlorobenzenes are very efiective. However,to obtain the improved exhaust valve life described above, the brominecontent of the fluid or fuel should be increased 15 to 20 percent abovethose of the standard prior art compositions. An increase in chlorinecontent without an accompanying increase in bromine does not appear togive any improvement. On the otherhand, a

gdecrease in chlorine content Without compensating increases in brominesignificantly reduces the scavenging.

The minor proportions of the improved antiknock fluids of the presentinvention which are employed in fuels for internal combustion enginesare the same as with conventional antiknock fluids. Thus, in providingimproved fuels for automotive engines and the like, amounts of theimproved antiknock fluids of the present invention equivalent to up to2.5 or 3 .milliliters of tetraethyllead per gallon are used. Inproviding improved fiuels for use in aviation engines, amounts of theimprovedantiknoolt fluids of the invention equivalent to up to 6milliliters of tetraethyllead per gallon can be used.

Although the antiknock agent utilized in the improved antiknock fluidsof the present invention can be any of the diverse organolead compoundspossessing antilcnock activity, a preferred embodiment of the presentinvention consists of improved antiknock fluids comprising thephosphorus-containing materials and the halide corrective agents orscavengers in combination with tetraalkyllead' compounds, particularlytetraethyllead. Likewise, the socalled mixed alkyllead antiknocks whichhavefrorn time to time been proposed can be so employed, such as, forexample, mixtures of the various methylethyllead antiknocks, such asmethyltriethyh, dimethyldiethylandtrirnethylethyllead as well astetramethyllead itself.

In compounding the improved antiknock fluids of the instant invention,phosphorus compounds that are mutually soluble organolead compoundsand/or in organic halides are the simplest to use. Those phosphoruscompounds which do no't possess the requisite solubility in theaforesaid organic materials can be incorporated with the help of acommon solubilizing agent, such as acetone or alcohol. In some cases,the maximum solubility of the phosphorus compound is adequate but thesolution rateis low, so that it is advantageous to warm and/ or agitatea mixture of the components'of the improved antiknock fluids of thepresent invention in compounding operations.

In order to demonstrate the beneficial eifects of the invention, thefollowing specific examples are given:

EXAMPLE I To 1000 gallons of a commercial blend of straight-run andcatalytically and thermally cracked stocks was added three liters oftetraethyllead in a fluid containing 1.0 theory of chlorine as ethylenedichloride, and 0.5 theory of bromine as ethylene dibromide. Theresulting blend was intimately mixed producing a homogeneous fuelcomposition containing 3.0 milliliters of tetraethyllead per gallon. Atruck containing a standard six-cylinder I-head engine having adisplacement of 235 cubic inches and a 6.7 to 1 compression ratio wasoperated with this fuel under heavy duty road operating conditions untiltwo exhaust valve failures were detected. It was found that under suchheavy duty road operating conditions the truck ran an average of 17,040miles before two valve failures.

13 EXAMPLE H To 1000 gallons of the commercially availablefuel describedin the preceding example was added 3 liters of tetraethyllead in a fluidcomprising 1.0 theory of chlorine as ethylene dichloride, 0.5 theory ofbromine as ethylene dibromide and 0.2 theory of phosphorus as tricresylphosphate. A homogeneous fuel composition was producedv by intimatelymixing the aforementioned components which thus contained 3.0milliliters of tetraethyllead EXAMPLE HI To 100 gallons of thecommercial base stock described in Example I was added 300 millilitersof tetraethyllead in a fluid containing 1.0 theory of chlorine asethylene dichloride and 0.5 theory of bromine as ethylene dibromide. Theresulting blend was intimately mixed producing a homogeneous fuelcomposition containing 3.0 milliliters of tetraethyllead per gallon. Amodern sixcylinder truck engine was operated on the aforementioned fuelcomposition for a period of 387 hours under light duty cycling serviceoperating conditions. It was found that during this period of operation,no exhaust valve failures occurred.

EXAMPLE IV To 100 gallons of the commercial base stock described inExample I was added 300 milliliters of tetraethyllead as a fluidcomprising 1.0 theory of chlorine as ethylene dichloride, 0.5 theory ofbromine as ethylene dibromide and 0.2 theory of phosphorus as tricresylphosphate. The resulting blend was intimately mixed producing ahomogeneous fuel composition containing 3.0 milliliters oftetraethyllead per gallon. The same truck engine as described in thepreceding example was operated under the same light duty cycling serviceoperating conditions until two exhaust valve failures were detected. Itwas found that the average time required for such failures was 140hours. Therefore, the incorporation of phosphorus-com taining materialsin an anti-knock fluid in accordance with the teachings of the prior artproduced a reduction in exhaust valve life amounting to 63.8 percent.

EXAMPLE V To 100 gallons of a standard paraftinic fuel containing 0.003percent of sulfur was added 400 milliliters of tetra- V ethyllead as afluid comprising 1.2 theories of bromine as ethylene dibromide (EtBr and0.1 theory of phosphorus as tricresyl phosphate (TCP). The resultingblend was intimately mixed producing a homogeneous fuel compositioncontaining 4.0 milliliters of tetrethyllead per gallon, that is, one ofthe improved antiknock fuels of the present invention was provided. Asingle-cylinder laboratory test engine having a 17.6 cubic inchdisplacement and equipped with a hemispherical combustion chamber wasoperated on the aforementioned improved fuel containing one of theimproved antiknock fluids of the present invention for a period of 100hours under conditions such that the exhaust valve throat temperaturewas 1450 F. The same engine was then operated on three otherphosphorus-containing fuels produced by adding to the 14 standardparaflinic' fuel antiknock fluids containing phos'-- phorus materials inaccordance with the teachings of the prior art. The criteria for exhaustvalve performance were the weight loss of the exhaust valve whichoccurred during hours of engine operation and the reduction in exhaustvalve throat area during the same period of time. The data are presentedin Table I.

Table I Exhaust Reduction in valve weight exhaust valve Fluid Mix lossper 100 throat area hours, grams per 100 hours,

percent 1.2 '1 EtBm+0.1 T TOP 0. 41 3. 6 1.0 T EtBn+0.2 '1 TOP 1. 77 14.9 1.0 T EtBrg+0.l '1 'IGP-... 1. 74 14. 4 1.0 I EtBlz+0.05 T TOP 0.605.6

EXAMPLE VI on the improved antiknock fuel containing one. of the'improved antiknock fluids of the present invention for a period of 100hours under conditions such that the exhaust valve throat temperaturewas 1385" F. The same engine was then operated on two otherphosphoruscontaining fuels produced by adding to the standard paraffinicfuel antiknock fluids containing phosphorus materials in accordance withthe teachings of the prior art. As in the preceding example, thecriteria for exhaust valve performance were the weight loss of theexhaust valve which occurred during 100 hours of engine operation, andthe reduction in exhaust valve throat area during the same period oftime. The data are shown in Table II. 7

Table II (DON EXAMPLE VII Road tests-multi-cylinder engines.A fleet ofstandard 1953 automobiles was operated on the road under controlleddriving conditions. These fleet tests were designed to study the effectof various fuel additive com binations on the engine durability of thetest cars. One criterion in this series of tests was the effect of thesefuel additive combinations on exhaust valve life.

The vehicles were operated on a closely controlled 60 miles per hourtop-speed schedule and accumulated approximately 5000 miles per week atan average speed of 54 miles per hour. The cars were equipped with newcylinder heads and standard exhaust valves at the beginning of the test.These cars were then operated. on the road under the above conditionsuntil an exhaust valve failure was detected. The defective valve wasthen re- 7 moved and replaced with a new valve and the test oontinneduntil a second valve failure occurred. Thus, in each test the exhaustvalve life was expressed as the average of the number of miles to thefirst failure and the number of miles to the second failure.

The cars were operated on the same test gasoline and crankcaselubricating oil. The inspection data of the fuel and lubricating oilused are as follows:

FUEL

Process composition, percent vol.: 7

Straight run 100- TEL content, ml./ gal 3.00 Dissolved gum, mg./ 100 m10.4 Oxidation stability, min 1440 Total sulfur, percent weight 0.006Gravity, API 66.7 Vapor pressure, p.s.i 6.6 Distillation, F.: 1

Initial evaporation 10% evaporated 50% evaporated 184 90% evaporated 239Final evaporation"; 300

Octane number: F-l (research)-.. 91.8 F-Z (motor) 88.4 Hydrocarbon type,percent vol.: e I

Parafiins Olefins I Aromatics 8 Naphthenes 34 OIL In all of the teststhe above test gasoline contained 3 milliliters of tetraethyllead pergallon. In one series of tests this leaded fuel contained 0.5 theory ofbromine as ethylene dibromide and 1.0 theory of chlorine as ethylenedichloride. In another series of tests this leaded fuel contained 0.5theory of bromine as ethylene dibromide, 1.0 theory of chlorine asethylene dichloride and 0.2 theory of phosphorus astri-(fi-chloropropyl)-thionophosphate, which is herein designated asphosphorus additive A. 'In a third series oftests the leaded fuelcontained 0.6 theory of bromine as ethylene dibromide, 1.0 theory ofchlorine as ethylene dichloride and 0.2 theory of phosphorus asphosphorus additive A. As used herein, the term ftheory is used in .itsestablished sense in the-art.-

16 One theory of bromine or chlorine is defined as the amount thereoftheoretically required to react with the lead to form lead bromide orlead chloride, respectively. Thus, one theory of these halogens is twoatoms of halogen per atom of lead. The term theory as applied to thephosphorus fuel additive is defined as the amount of phosphorustheoretically required to react with the lead to form leadorthophosphate, that is, two atoms of phosphorus per each three atoms oflead. For example, a phosphorus concentration of 0.2 theory (T) isequivalent to a phosphorus-to-lead atom ratio of 0.413.

The results of these road tests are shown in Table Ill.

Dynamometer tests-multi-cylinder engines-Another series ofdurabilityengine tests. designed to demonstrate the. effect of.variousfuel additive combinations on exhaust valve life wasconducted. In thesetests a standard 1953 automobile engine attached to an enginedynamorneter was operated at 2500 r.p.m. constant speed with alternatethree-minute periods at half throttle and at full throttle. This enginewas operated under these conditions until an exhaust valve failure wasencountered. The defective valve was removed and replaced with a newvalve and the test Iecontinued until a second valve failure occurred. Inthisinstance, the criterion of exhaust valve life in any one test wasthe average of hours to the first failure and hours to the secondfailure.

The engine was operated on a commercial gasoline containing 3.0milliliters of tetraethyllead per gallon. The inspection data of thetest gasoline are as follows FUEL Process composition, percent vol.:

Catalytically. cracked 92 Thermally cracked 6 Reformed 2 TEL content,mL/gal 3.00 Dissolved gum, mg./ ml 0.7 Oxidation stability, min 790Total sulfur,--percent weight 0.043

1 Includes naphthenes.

v nude.

17 The crankcase lubricating oil was the same as that used in themulti-cylinder engine road tests described hereinabove.

Tests were made to show the effect of three different fuel additivecombinations on exhaust valve life. One

such combination was 0.5 theory of bromine and 1.0;"

theory of chlorine as ethylene dibromide and ethylene dichloride,respectively. Another fuel additive combina-' tion tested was 0.5 theoryof bromine as ethylene dibromide, 1.0 theory of chlorine asethylenedichloride and 0.2 theory of phosphorus as phosphorus additive -A.

The other combination tested was 0.6 theroy of bromine as ethylenedibrcmide, 1.0 theory of chlorine asethylene dichloride and 0.2 theoryof phosphorus as phosphorus additive A.

The data obtained from these tests are shown in Table IV.

Dynamoineter tsts-single-cylinder engines.-Another series of enginetests was conducted to determine the effect of various fuel additivecombinations on exhaust valve life. In these tests the test equipmentcomprised 17.6 single-cylinder engines attached to engine dynamometers.These engines were equipped with XOR exhaust valves and Stellite No. 3exhaust valveseat inserts. These engines were operated at 2700 r.p.m.,100 F. intake air, 212 F. jacket temperature and a fuel-air ratio of0.07. These conditions resulted in a valve throat operating temperatureof l540 F.:30 F.

The gasoline used was a standard reference fuel, technical isooctane,containing 3.0 milliliters of tetraethyllead per gallon. The sulfurcontent of gasoline was adjusted to 0.05 percent by weight of sulfur bythe addition of disulfide oil. A conventional Grade 1120 avia- Totalsulfur, percent wt 0.-17

In series of tests the criterion of exhaust valve life was the averagehours required to produce an exhaust valve failure. A

The fuel additive combinations studied in series 1 phosphorus asphosphorus additive A. The phosphorus content of fuel additivecombinations designated above as (2) and (3) was such that thephosphorus-to-lead atom ratio was 02:3 in each instance. 1

The results of these engine tests are shownin Table Vt Table V Phds-Relaphorus Num- Hours tlve Halohydrocarbon scavenger addiber of totailhours tive tests ure to iailcone. I we 0.5 T of'bromine (ethylene"dibromide), 1.0 T of chlorine (ethylene dichloride) None 3 120 100 Do0.11 3 108 90 0.6 'I of bromine (ethylene dlbromide), 1.0 T of chlorine(ethylene dichloride) 0.1'1 3 205 171 l P:Pb=0.2:3.

EXAMPLE X Recognizing the fact that exhaust valve throat corrosion was aproblem in some aircraft engines with some valve materials, a series oftests was initiated to determine the extent by which this objectionablecorrosion was increased by the use of phosphorus additives and means'bywhich it might be reduced. In series of tests, 17.6 engines coupled toengines were equipped with either of two types of exhaust valvesfabricated by an exhaust valve manufacturer of materials currently inuse for large aircraft engine valves.

The engines were operated at 2700 r.p.m., 0.07 fuelair ratio, 20 sparkadvance, F. intake air temperature, 212 F. jacket temperature and at anindicated mean efiective pressure (I'M-EP) of 114' (a nieasure of poweroutput). V

The gasoline used in these tests .was technical isooctane and contained4.0 milliliters of tetraethyllead per gallon and had a sulfur content of0.003 percent by weight. A commercially available crankcase lubricatingoil, Aviation Grade 1120, was used in the engines. This inspection datafor this oil are set forth in the description concerning the nextpreceding series of tests.

In all, six engine tests were conducteithree tests using exhaust valvesfabricated of one type of materials of construction and the remainingthree tests using exhaust valves fabricated from other materials ofconstruction. Each of these two types of valves was representative ofexhaust valves used in aircraft engines.

Three different fuel additive combinations were tested. One suchcombination involved use of the above leaded fuel containing 1.0 theoryof bromine as ethylene dibromide. Another combination was that the aboveleaded gasoline contained 1.0 theory of bromine as ethylene dibromideand 0.1 theory of phosphorus as tricresyl phosphate. The third fueladditive combination used was 1.2 theory of bromine as ethylenedibromide and 0.1 theory of phosphorus as tricresyl phosphate.

In these tests the measures of exhaust valve performance were thecorrosion of the exhaust valves measured by weight loss of the valvesincurred per 100 hours of engine operation and the'reduction in thethroat area of the exhaust valves incurred per 100 hours of engineoperation. v

The results of these engine tests are shown in Table Table VI axnausr-vs-Lvn MATERIAL 1'.

p Phos- Valve-weight "Reduction in r phorus loss, gin/100 thrust aresTest Halohydrocarbon addi- Hours scavenger tive cone. Gr. Hrs. .Per-Percent 7 cent 100 hrs.

1 1.0 'r of bromine (ethylms V 240 0.659 0.274 o a ene dlbromlde). 2;--.do- 0.1 '1'. g 150 2.613 1.74 23.8 15.9 a 1.2 T of bromine (ethyl- 1 o.1 T 240 0. 975 u; 405 8.7 3.03

sue dibromide) nxnansr VALVE m'rnnmn 2..

4 1.0 'r of bromlnetethyl None 240 a. 060 1. 214 s; 1 an:

em dibromlde): a; d 0.1 T 150 a. 904 2. so 24. 0 16. 0 o. 1.21 orbromine (ethyl- 1 0.1 T 240 a. 273 1. as 22. 0 9.17 ens dthromide).

I P:Pb=0.2:3.

The same degrees of improvement are obtained by emamount of metalliclead present insuch solids. These reploy flg .infuels, for internalcombustion engines minor proportions of such fluids as, for example,tetraethyllead in combination with 1.2 theories of bromine as thevarious isomers of dibromotoluene, and 0.1 theory of phosphorus astriphenylthiophosphite; tetraethylleadin combination with 1.0 theory ofchlorineas ethylene dichloride, 0.6 theory of bromine as ethylenedibromide, ,andftll theory .of phosphorus, as triphenylphosphite;tetraethyllead in combination with 1.1 theories ofehlorine as ethylenedichloride, 0.6' theory of bromine as ethylenedibromide, and 0.15 theoryof phosphorus as dibutylbenzenephosphonate; tetraethyllead incombination with 1.4 theories of chlorine as ethylene dichloride, 0.6theory of bromine a's ethylene dibromide, and 0.2 theory ofphosphorus astricresylthiophosphate; tetraethyllead in combination with 1.0 theory ofchlorine-as 1,2,4-trichlorobenzene, 061th cry of bromine asdibromotoluene,and 0.1 theory of phosphorus asdiphenylbenzenethionophosphonate; tetraethyllead in combination with 1.0theory of'chlorine as 1,2-dichloroethane, 0.6 theory of bromine as1,2-dibromoethane and 0.1 theory of phosphorus as diphenylnrono-'cresylphosphate; tetraethylleadin combination-"with- 1.2

theory-of chlorine as hexachlorocyclohexane, 0.6- theory ofbromine ashexabromocyclohexane, and 0.15 theory of phosphorus asdiphenylpliosphine; tetramethyllead in combination with 1.4 theories ofchlorineas-'-1,2,4-trichlorobenzene, 0.6 theory of bromine asdibromotoluenes, 0.05 theory of phosphorus as diphenylbutylphos--phinite;. tetrabutyllead in combination with: 1.1 theories of chlorineas 1,2-dichloroethane, 0.6 theory of bromine as 2-bromo-2-methylpropane,0.1.theory of phosphorus as dicresylbenzenethiophosphonate, and thelike. 7

An additional advantage produced by the improved antiknock fluids of theinstant invention is the fact that some of the phosphoruscontainingmaterials described 'hereinbefore, such as tricresylphosphate,triphenylphosphate, and pyrocatecholphosphite, impart to such fluids-the stabilizing or antioxidant eflectiveness' of such materials.Furthermore, some of the phosphorus-containing materials, suchastriphenylphosphite, tricresylphosphitc, tricresylphosphate,trilaurylphosphite, and tri-(p-tertbutylphenyD-phosphate, are known toalleviate corrosion problems particularly in fuel storage tanks madeofaluminum, magnesium, and diversealloys thereof. Moreover,

some of the phosphorus-containingmaterials, such as tri- (3chloropropyl)thionophosphate, dimethyltolylphosphate, anddimethylxylylphosphate, are particularly good preignition suppressants-Additional advantages of the improved antiknock [fluids and fuels of thepresent invention are the reduction of the total amount of solidsnormally found in the crankcase'and a reduction in the total ductionslessen the likelihood of interferences with normal oil flow andlubrication of critical engine parts. e

In compounding some of the improved antiknock fluids of the presentinventioml can also employ other antioxidants and other stabilizingcompositions including ortho dialkylated phenols andN,N'-di-sec-butyl-p-phenylene. diamine. .PFnrthermore, I can also employdiverse or: ganic dyes and the like which have long been recognized inthe prior art, in such improved antiknock fluids of the presentinvention. 7 I

The improved antiknock fluids of this invention can be effectivelyutilized by supplemental injection into internal combustion engines andin dual fuel systems. Likewise, concentrated fuels containingsubstantially greater amounts of my antiknock fluids'than ordinarytreated fuels for internalcombustion engines can be utilized. in thismanner.

Having fully described myinvention, the need therefor, and the bestmethod devised for carrying it out, it is not intended thatit be limitedexcept within the spirit and scope of the appended claims.

I claim:

1. In an antiknock composition consisting essentiallyof organoleadmaterial as theprincipal antiknock ingredient, organic halogen scavengermaterial selected from the class consistingof that having two atoms ofchlorine plus one atom of bromine per atom of said anti-knock lead, andthat having. two atoms of bromine per atom of said antilcno'ck lead, and'a gasoline soluble phosphorus-containing, spark pluganti-fouling'compound, the phosphorus-to-lead atom ratio of saidcomposition being from about 0.02:3 to about 0.7:3; the improvement inwhich the bromine contentotf the organic halogen scavenger material isincreased by..about 15 to. 20 percent. r Y

2. In an antiknock composition consisting essentially of tetraethyllead,ethylene dichloride, ethylene dibromide, and a gasoline solublephosphorus-containing, spark plug anti-fouling compound, thephosphorus-to-lead atom ratio of said composition being from about 0.153to about 0.423, and the ethylene dichloride content being that whichfurnishes about'tw'o atoms of chlorine for every atom of lead, theimprovement in which .the ethylene dibromide content is such that forevery atom of lead therearelz atoms ofbromine. f

3. The "antiknock oompositionof claim 2 wherein thephosphorus-containing compound is tricresylphosphate.

4. The antiknock composition of claim 2 wherein thephosphorus-containing compound is tri-B-(chloropropyl) thionophosphate.I

5. In anantiknock composition consisting essentially of tetraethyllad,ethylene dibromide and a gasoline sol- References Cited in the file ofthis patent UNITED STATES PATENTS Bartholomew Apr. 9, 1946 Yust et a1.Oct. 2, 1956 FOREIGN PATENTS Great Britain Apr. 2, 1948 Belgium Jan. 31,1951

1. IN AN ANTIKNOCK COMPOSITION CONSISTING ESSENTIALLY OF ORGANOLEADMATERIAL AS THE PRINCIPAL ANTIKNOCK INGREDIENT, ORGANIC HALOGENSCAVENGER MATERIAL SELECTED FROM THE CLASS CONSISTING OF THAT HAVING TWOATOMS OF CHLORINE PLUS ONE ATOM OF BROMINE PER ATOM OF SAID ANTI-KNOCKLEAD, AND THAT HAVING TWO ATOMS OF BROMINE PER ATOM OF SAID ANTIKNOCKLEAD, AND A GASOLINE SOLUBLE PHOSPHORUS-CONTAINING, SPARK PLUGANTI-FOULING COMPOUND, THE PHOSPHORUS-TO-LEAD ATOM RATIO OF SAIDCOMPOSITION BEING FROM ABOUT 0.02:3 TO ABOUT 0.7:3, THE IMPROVEMENT INWHICH THE BROMINE CONTENT OF THE ORGANIC HALOGEN SCAVENGER MATERIAL ISINCREASED BY ABOUT 15 TO 20 PERCENT.
 6. A GASOLINE CONTAINING THECOMPOSITION OF CLAIM 1 IN AMOUNT SUFFICIENT TO PROVIDE EFFECTIVELYIMPROVED ANTIKNOCK, BUT NOT MORE THAN EQUIVALENT TO SIX MILLILITERS OFTETRAETHYLLEAD PER GALLON.